1. Field
The following description relates to a cylindrical electromagnetic bandgap capable of improving electromagnetic interference (EMI) and a coaxial cable having the same.
2. Description of the Related Art
In general, EMI (electromagnetic interference) has been considered a chronic problem in operating an electronic device with a high frequency.
RFI (Radio Frequency Interference) is an electromagnetic interference that occurs inside a product, and such phenomenon particularly reduces the function of wireless reception. The operating frequencies of recent electronic products range from several hundred MHz to several GHz. Accordingly, as various wireless functions such as wireless Internet, GPS, WiFi, or Bluetooth, for example, have been adopted, the effect of an EMI or a RFI has received significant attention.
Also, for electronic products that use RF cables, such as notebook PCs, tablet PCs, or handheld phones, for example, the noise of electromagnetic waves developed inside the system interferes with the cable, resulting in induced common-mode currents that affect a signal received through an antenna, and degrade the reception sensitivity.